Recent experiments have shown that although the corpus striatum is histologically and histochemically homogeneous, it can be anatomically partitioned by behavioral criteria of function. The proposed experiments are designed to continue our studies of whether striatal dopamine is involved in different behaviors depending on where it is released in the striatum. Using crystalline and solution microinjections of 6-hydroxydopamine (6-OHDA) into the rat striatum, we plan first to investigate the amount of regional cerebral dopamine and norepinephrine depletion using a fluorometric technique. These biochemical changes will then be related to our ongoing and previously completed behavioral studies of the same injections. A number of behavioral tests are proposed to investigate the nature of behavioral changes after 6-OHDA injections into the ventral anterior striatum. These tests include selfstimulation, avoidance, and classical conditioning. In some of these experiments, dopamine will be applied to attempt to influence behavior in the opposite direction to 6-OHDA. A second set of experiments is designed to explore components of the lateral hypothalamic syndrome seen with central striatal dysfunction. It is hoped that some of these phenomenona might be possible animal analogues of componenets of Parkinson's disease in humans.